The invention relates to a process for producing or packing an item with a limited period of use or interest and a consumer item produced according to this process.
The printing of the date of production onto consumer goods (e.g. foodstuffs, medicaments, pharmaceutical products, film material, dyes, adhesives etc. which have a limited period of use), or onto the packaging thereof is known. The date of issue is also indicated on journals and papers thereby providing information on the actual date.
A due date, is, moreover indicated on many consumer goods which provides information on how long they can be preserved, but which does not give an indication of the actual time (and thus no indication on the real degree of freshness).
DE-OS 30 48 426 also discloses a process for detecting the actual state of an item of consumption. Here, a mark is arranged on the item of consumption, whose characteristics change under the conditions in which the product to be controlled changes from a state of usability into one in which it is no longer fit for use. In order to ascertain the state of usability, this mark must be combined with a separate sensing unit. This known arrangement has the disadvantage that the actual time when the consumer item was first used cannot be ascertained and that an additional costly analysis has to be carried out in order to obtain clear information on the condition of the item.
Furthermore, a process is known from DE-OS 30 28 808 which enables a subsequent determination of the time of opening of a package of medicaments in order to control the use thereof. The packaging has a plurality of individual cavities separated from the outside air and from one another and a film closing these cavities. In order to remove the drugs, this film is broken thereby enabling the cavity to come into contact with the outside air. Depending on the length of exposure, the effect of the outside air changes the chemical and physical characteristics of a control substance additionally present in the cavities. The evaluation off the changed characteristics serves to determine the time of opening of the packaging of drugs. This process, however, requires a costly analysis which is a disadvantage and can, moreover, only be carried out with considerable expertise and is therefore quite unsuitable for universal use.
No known solution can provide information on the degree of freshness of the item in question without using an additional device.
All the known prior art devices for marking consumer goods have the disadvantage that they are unable to indicate to the consumer, in a clear, accurate and verifiable manner, the current state of these goods, especially if there is a particularly close time range between the production and use thereof.